Dental hand-piece and tool



Feb. 13, 1968 B. wElssMAN DENTAL HAND PIECE AND TOOL Filed NOV 26, 1965"lll/lll,

BY l l J l/ MVL United States Patent O 3,368,279 DENTAL HAND-PIECE ANDTOGL Bernard Weissman, 304 Ashland Place, Brooklyn, N.Y. 11217 FiledNov. 26, 1955, Ser. No. 509,794 14 Claims. (Cl. 32-27) The presentinvention relates to a `den-tal hanfdpiece and improved tool therefor.

The object `oi the present invention is to provide a highly novel andeiii'cient dental tool dor use with a dent-al hand-piece. Other andfurther :ob-jects y'and advantages |will be readily apparent to oneskilled -in the ait from a consideration of the following sneciicationtaken in lconne'c-tion with the appended drawing.

'In `the drawing, which illustrates the best mode 4presently`contemplated `ifor 'carrying out the invention,

FIGURE l1 illust-rates ya dental hand-.piece lof the 'contraangle typeembodying the present invention showing a tool in the process of beinginserted therein;

FIGURE 2 is lan elevational view of la dental tool in accordance withthe present invention;

FIGURE 2A `is a lfragmentary `sectional view .on `an enlarged scaletaken on the line 2a-2a of FIGURE 2;

FIGURE -3 is a fragmentary view of the handapiece head when viewed inthe direction of the arrows y3 3 of FIGURE 1 vshowing the tool lock inopen position;

FIGURE 4 is la sectional view of the hand-'piece taken along the Iline'4-4 of FIGURE 1;

FIGURE 5 is a sectional view of the handpiece -with the tool indisengaged position therein taken along the line 54S olf FIGURE 4;

FIGURE 6 'is `a sectional View taken lalong the line 6-6 of FIGURE 5;

`FIGURE 7 is a sectional view 'taken along the line 7-7 of FIGURE 5;`and FIGURE l8 'is `a view similar to FIGURE 7 showing the tool inenga'ged b-ondition in the handpie'ce head.

FIGURES l, 3 and 4 illustrate a contra-angle tool holder for a .dentalhandepiece which tool holder embodies the instant invention. The toolholder may be of generally conventional :form las used in the practiceof dentistry and is design-ated generially by the reference numeral 110.A lcontraJangle tool holder of the type to which the present inventionpertains, generally includes a :coupling member .11 which is provided atone end with a tubular sleeve l1l2. The coupling member '1"1 is `adaptedto receive 'the chuck end of a dental lhandpie'ce which is notillustrated. 'Ihe coupling member 11 mounts la drive shaft f1'3 which is.gripped in 'the ichuck of the h-anclpiecc so that it can be rotated bythe dental engine. The coupling member |1\1 also mounts la couplingshaft 14 which is in operative connection with and disposed lat an anglewith .respect t-o lthe drive :shaft 1-3 so `as to be driven thereby. Thecoupling shalt 14 extends into the tubular sleeve lf2. The sleeve lisreleasably locked t-o the coupling member by means of la spring biaseddetent '15 which is engagezrb'le in one of the apertures 116 provided inthe sleeve. A linger piece i17 -is utilized 'to effect the disengagement.of the detent from the aperture.

The tubular sleeve 112 is provided with a housing 1S which mounts a'worm gear 19 and a pinion .gear ZG which is driven by the worm gear.The coupling shaft 14 drives the worm gear 19 by imeans of companionmeshed gears generally indicated by the reference numeral 21. As bestshown in FIGURE 5, the pinion lgear 20 is provided with a hollow core22. The core is substantially cylindrical in conorrnation except `at oneend thereof where it is provided 'with a ledge 23. The pinion gear 20 isretained in position within the housing 18 by means of a threaded nut 24lwhich is releasa'bly engaged within the housing.

3,368,279 Patented Feb. 13, 1968 Pursuant to the present invention,there is provided a tool which is .generally indicated 'by the referencenumeral 25. As here shown, the tool is `constitu-ted by a 'drill havingla body portion 26 from one end of which there extends a drill bit 27,'an elongated neck 2S extends from the other end of the body portion,land the neck is provided with an eccentric hea-d The body portion 26 islgenerally of lcylindrical conformation aand is provided with a.plurality of planar surfaces or rangs 3() which extend int-o the bodyportion trom lthe neck 28. Immediately `afd-jacent the neck 28, thetangs 36 provide the tool 25 with a substantially square cross-sectionlas best shown in FIGURE 2A.

The nut 24 is provide-d With a central aperture SI1 which is in registrywith the hollow core .22 provided in the pinion gear 20 as best shown inFIGURE l7. Consequently, it will be understood that the tool or drill 25may be inserted into the hollow passageway or core 2'2 of the piniongear l20 through lthe `aperture "31 lby grasping the drill bit 27 andinserting the head 29 through the aperture i31 `of the nut 24. Theeccentric head 29 must be rotated so as to @clear the ledge 23 las shownin FIG- URE 7. Thereafter, the tool y25 may be .rotated so that theeccentric head 29 is positioned relative to the ledge 23 so as toprevent the inadvertent disengagement of the tool iro-m the pinion gear.In order to lock the tool in the gear, provision is :made fior the llock32. 'Ihe look G2 is pivotally mounted -in a slot 133 defined in thehousing 1'8. The pivot rfor the lock 32 is constituted by a pivot screw34. The lock -32 is provided with a tinger piece 3'3 whereby it may bepivotally moved from its operative locking position to its inoperativedisengaged position as shown in FIGUR'E 3. The lock 32 is provided with`a locking slot 435 which is adapted to engage neck 28 of the tool 25 asbest sho-'wn in yFIGURES 5, 7 and 8.

It will be noted that the housing 118 is provided with an end aperture36 as best shown in FIGURE `8 which is in registry With the passagewayor core f2.2 provided in the pinion gear 20. `Pursuant to a feature ofthe present invention, provision is made for a leaf spring 37 which is4mounted on the exterior of the housing 118 by lmeans of the previouslymentioned pivot screw 34 'as best seen in FIGURE 5. The leaf spring G7is provided with ja depressed portion 68 which is normally biased by thespring into the housing aperture 36 as best shown in FIGURE 5.Furthermore, it will be noted that the spring portion '38 is engagedAWith the head 29 of the tool 25 so as to bias the tool to the positionthereof shown in 'FIG- URE 5. In said position, it will be noted 'thatthe tangs 30 Iare disengaged ir-om lthe ledge 23 with the result thatthere is no frictional engagement between the |tool land the pinion gear20. Consequently, the rotation of the latter .by the vvorm .gear 19:will not rotate the Itool 25. However, when the tool is moved inwardlyor the housing 18 in the direc-tion of the arrow '39 shoavn in FIG- URE8, tang portions 30 of the tool are frictionally engaged with the ledge23 so that the tool now is rotated by the pinion gear v20. Consequently,i-t will be apparent that the tangs :oi the tool fand the ledge of thepinion gear provide a clutching operation, the clutch being disengagedin the position tot the tool vshown vin FIGURE 5 and the clutch beingengaged or operative in the position thereof shown in FIGURE 8.

The foregoing clutching action is highly advantageous. For example, whenthe tool 25 is disposed in a patients mouth, the tool will normally bein the position thereof shown in FIGURE 5 being biased in said positionby the leaf spring 37 as shown in FIGURE 5 and FIGURE 7. Consequently,the tool Will not rotate and therefore while the tool is manipulatedwithin the patients mouth, there is no danger of the tool inadvertentlytouching any portion of the patients mouth. However, when the drill bit27 of the tool is forced against a tooth 40 as shown in FIGURE 8, thetool is moved inwardly of the housing 18 as indicated by the arrow 39against the bias of the spring 37 until the tool is wedged against theledge 23 so as to provide the desired frictional engagement. The toolbegins to rotate to perform the desired drilling op` eration.

When the drilling action is completed, the tool may be withdrawn fromthe bore hole in the tooth. As this is accomplished, the wedging actionreferred to above Continues to maintain the tool in rotary engagementwith the pinion so that the tool rotates and will not be broken duringthe withdrawal process. Upon complete withdrawal of the tool from thebore hole in the tooth, a slight finger pressure on spring 37 issuicient to disengage the tool and restore it to the position shown inFIGURES 5 and 7. The rotation of the tool is thus irnmediatelydiscontinued and the handpiece may then be repositioned as desired. Thearrangement permits the dental engine to be adjusted to any desiredspeed or torque before the tool begins to operate. Rotation begins onlyafter it has been firmly positioned in the desired location on the toothsurface and the requisite pressure has been applied. It will also beapparent that a buildup of speed or torque is thus avoided and fulltorque is immediately applied to the tool when pressure on the handpiececauses the tool to become engaged.

Although the invention has been illustrated in connection with a toolwherein the operative member is a drill bit 27, it will be understoodthat it may be applied with advantage to many other forms of dentaltools such as dental burrs or the like or to wrenches used for insertinganchoring members into teeth. In the latter ease, a further advantage isprovided in that the rotary motion of the wrench may be immediatelyarrested by application of finger pressure to the spring while thewrench is Still engaged with the dental anchor head.

It will be understood that various changes and modications may be madewithin the foregoing invention without, however, departing from thebasic inventive concept thereof as set forth in the appended claims. Itwill be noted that the tool may be readily withdrawn from the toolholder when desired by merely pivoting the lock 32 to the inoperativeposition thereof shown in FIGURE 3 so as to disengage the lock from thetool. In the event that the tool head 29 does not clear the ledge 23,the tool bit 27 may be grasped and rotated so that the head will clearthe ledge and the tool may then readily be withdrawn from the housing.

I claim:

1. A tool holder for a dental -hand-piece comprising a housing, adriving member mounted within said housing, said driving member beingadapted to removably receive a dental tool, and said driving memberhaving means cooperating with a dental tool to provide a clutchoperation.

2. A tool holder as in claim `1, said driving member having a hollowcore for receiving the dental tool, and said means being a portionextending into said Core for frictional engagement with the tool.

3. A tool holder as in claim 2, and resilient means provided on saidhousing to normally bias the tool out of engagement with said portion.

4. A tool holder as in claim said driving member having a hollow corefor receiving the dental tool, and said means being a ledge provided atone end of said core and extending into the latter for frictionalengagement with the tool.

5. In combination, a tool holder for a dental handpiece and a toolmounted by said holder, said holder comprising a housing and a drivengear mounted in said housing, said gear having a hollow core, said toolbeing mounted in said core, and cooperative means provided on said tooland said gear to constitute a clutch.

6. The combination as in claim 5, said core having a ledge definedtherein, and said tool having a portion frictionally engageable withsaid ledge to define said clutch.

7. The combination as in claim 6, and means normally biasing said toolportion out of frictional engagement with said ledge.

8. The combination as in claim 7, said housing having an aperture inregistry with said core, and said biasing means being a spring mountedby said housing and having a portion normally extending into said coreto engage said tool.

9. A dental tool having an elongated body portion, an operative memberprovided at one end of said body portion, a neck provided at the otherend of said body portion, an eccentric head provided on said neck, andclutch formation means extending from said neck into said body portion.

10. A dental tool as in claim 9, said clutch formation means beingplanar tang surfaces.

lil. A dental tool as in claim 10, said tool having a squarecross-section at said tang surfaces.

12. A dental tool as in claim 9, wherein the operative member is adrill.

13. A dental tool as in claim 9, wherein the operative member is a burr.

14. A dental tool as in claim 9, wherein the operative member is awrench element.

References Cited UNITED STATES PATENTS 2,866,530 12/1958 Charlat 192-673,314,153 4/1967 Maurer 32-27 LOUIS G. MANCENE, Primary Examiner.

C. R. WENTZEL, Assistant Examiner.

1. A TOOL HOLDER FOR A DENTAL HAND-PIECE COMPRISING A HOUSING, A DRIVINGMEMBER MOUNTED WITHIN SAID HOUSING, SAID DRIVING MEMBER BEING ADAPTED TOREMOVABLY RECEIVE A DENTAL TOOL, AND SAID DRIVING MEMBER HAVING MEANSCOOPERATING WITH A DENTAL TOOL TO PROVIDE A CLUTCH OPERATION.